Absent from those few categories where the law allows content-based regulation of speech is any general exception to the First Amendment for false statements. This comports with the common understanding that some false statements are inevitable if there is to be an open and vigorous expression of views in public and private conversation, expression the First Amendment seeks to guarantee. See Sullivan, supra, at 271, 84 S.Ct. 710 (“Th[e] erroneous statement is inevitable in free debate”). Pag 2544

Permitting the government to decree this speech to be a criminal offense, whether shouted from the rooftops or made in a barely audible whisper, would endorse government authority to compile a list of subjects about which false statements are punishable. That governmental power has no clear limiting principle. Our constitutional tradition stands against the idea that we need Oceania’s Ministry of Truth. See G. Orwell, Nineteen Eighty-Four (1949) (Centennial ed.2003). Were this law to be sustained, there could be an endless list of subjects the National Government or the States could single out. Where false claims are made to effect a fraud or secure moneys or other valuable considerations, say offers of employment, it is well established that the Government may restrict speech without affronting the First Amendment. See, e.g., Virginia Bd. of Pharmacy, 425 U.S., at 771, 96 S.Ct. 1817 (noting that fraudulent speech generally falls outside the protections of the First Amendment). But the Stolen Valor Act is not so limited in its reach. Were the Court to hold that the interest in truthful discourse alone is sufficient to sustaina ban on speech, absent any evidence that the speech was used to gain a material advantage, it would give government a broad censorial power unprecedented in this Court’s cases or in our constitutional tradition. The mere potential for the exercise of that power casts a chill, a chill the First Amendment cannot permit if free speech, thought, and discourse are to remain a foundation of our freedom. Págs. 2547-48.